You could be forgiven for thinking that it is relatively simple matter to build a Facebook application or to integrate Facebook Connect into your website, request access to users’ profile information (and get it) and use that data for pretty much whatever you need to do with it. Unfortunately that is just not the way it works when it comes to Facebook user data.
This is a great piece on the Facebook developer site about the ambiguities of the Facebook TOS as it applies to keeping Facebook user data. As I’m working on a project thats directly related to this, I found this article invaluable.
via Facebook | web.tech.law: Legal labyrinth for Facebook developers: storing and using user data.